Determinantes de la estructura de endeudamiento de empresas latinoamericanas emisoras de ADRS

The objective of this article is to analyze the determinants of the financial leverage of a sample of Latin American companies that issued ADRs. This constitutes the first study in this area. We consider a sample of thirty-two public firms that issued ADRs in NYSE market during 1990-1994. According to the model proposed by Rajan and Zingales (1995) we find similar results in three of the four variables explored by these authors. Our results show a negative relationship between growth opportunities and leverage. Secondly, there is a positive relation between size of the company and leverage. Furthermore, profitability is negatively related to leverage. Finally, tangibility shows to be statistically significant but with an unexpected negative relationship with the leverage. This last result is not consistent with previous evidence in the corporate finance literature.El propósito de este trabajo es investigar los determinantes de la estructura de endeudamiento de empresas latinoamericanas que han emitido ADRs, lo cual no ha sido cubierto por la investigación previa. Para ello se utiliza una muestra de 32 compañías latinoamericanas que emitieron ADRs en la bolsa de valores de Nueva York (NYSE), en el período 1990-1994. Aplicando el modelo propuesto por Rajan y Zingales (1995) para explicar los determinantes de la estructura de endeudamiento a nivel internacional, para el período 1994 a 1996 los resultados señalan que existen tres variables comunes entre empresas norteamericanas y los emisores de ADRs que explican la estructura de endeudamiento, coincidiendo con la hipótesis formulada. Se observa una relación inversa entre oportunidades de crecimiento y nivel de endeudamiento. Además, al igual que en muchos estudios empíricos del área, la variable tamaño está positivamente asociada con el leverage. Finalmente, la rentabilidad está negativamente relacionada con el nivel de endeudamiento. El sentido explicativo de la variable activos tangibles resultó de signo contrario a la evidencia presentada por Rajan y Zingales, es decir, los resultados muestran una relación negativa entre esta variable y el leverage

Resultados preliminares de fertilizaciones artificiales realizadas con esperma crioconservado de rodaballo Scophthalmus maximus (Linnaeus, 1758)

Se crioconservó una mezcla de esperma procedente de cuatro machos sometidos a control de fotoperíodo. Después de valorar individualmente el esperma, la mezcla fue homogeneizada y preparada para la crioconservación. Se utilizaron dos diluyentes diferentes: la solución salina modificada de Ringer y la solución de Mounib, a los que se añadió como crioprotectores un 10% de yema de huevo y un 10% de dimetil sulfóxido (DMSO). Las relaciones esperma-diluyente utilizadas fueron 1:2 y 1:3. Una vez congelado en nitrógeno líquido a -196°C, se mantuvo durante 24 horas, período tras el cual fue descongelado y utilizado en la fecundación artificial. Las tasas de fecundación (85-92%) y de eclosión (23-35%) obtenidas con esperma crioconservado no difieren significativamente para los dos diluyentes ni para las dos diluciones (p < 0,001).Publicado

Effects of in vivo treatment with the dopamine antagonist pimozide and gonadotropin-releasing hormone agonist (GnRHa) on the reproductive axis of Senegalese sole (Solea senegalensis)

Publicado

Estudio preliminar sobre una posible inhibición dopaminérgia en la reproducción del lenguado senegalés (Solea senegalensis)

El objetivo del presente estudio fue evaluar el efecto del sistema dopaminérgico sobre la reproducción del lenguado senegalés (Solea senegalensis). Para ello, reproductores de lenguado senegalés nacidos y criados en cautividad (generación F1) fueron tratados con 1) GnRHa, 2) inhibidor dopaminérgico (pimozide) o 3) un tratamiento combinado (GnRHa + pimozide). El efecto de los tratamientos se evaluó a nivel de producción de huevos y esperma (cantidad y calidad); además se estudió el efecto sobre niveles plasmáticos de esteroides sexuales y desarrollo gonadal (histología). Las hembras no mostraron una estimulación en la ocurrencia de puestas por el tratamiento combinado GnRHa + pimozide respecto a aquellas tratadas solo con GnRHa. Sin embargo, los machos que recibieron el tratamiento combinado mostraron una mayor estimulación en la producción de esperma y en el grado de maduración testicular respecto a aquellos que recibieron solo GnRHa o pimozide. Los resultados indican que el sistema dopaminérgico no parece ejercer una acción fuerte sobre la ocurrencia de puestas en hembras, aunque podría estimular la espermiación en machos de lenguado senegalés.Preliminary study on dopaminergic inhibition in Senegalese sole reproduction (Solea senegalensis) The aim of the present study was to evaluate the effect of the dopaminergic system on Senegalese sole (Solea senegalensis) reproduction. For this purpose, Senegalese sole breeders hatched and raised in captivity (F1 generation) were treated with 1) GnRHa, 2) a well-known dopaminergic inhibitor (pimozide) or 3) a combined treatment (GnRHa + pimozide). The effect of each treatment was determined by studying spawning occurrence and sperm (quantity and quality); in addition, effects on sex steroids levels and on gonadal development (histology) were also considered. Females did not show any improvement of spawning occurrence by combining GnRHa and pimozide respect to those females treated only with GnRHa. However, males which received the combined treatment showed a greater stimulation of sperm production and testicular maturity than those males treated with a single GnRHa or pimozide treatment. Our results indicate that dopaminergic system do not seem to play a strong action on eggs spawning in females, but may stimulate spermiation in Senegalese sole males

New structural insights into the role of TROVE2 complexes in the on-set and pathogenesis of systemic lupus eythematosus determined by a combiantion of QCM-D and DPI

The final publication is available at link.springer.com.[EN] The mechanism of self-recognition of the autoantigen TROVE2, a common biomarker in autoimmune diseases, has been studied with a quartz crystal microbalance with dissipation monitoring (QCM-D) and dual polarization interferometry (DPI). The complementarity and remarkable analytical features of both techniques has allowed new insights into the onset of systemic lupus erythematosus (SLE) to be achieved at the molecular level. The in vitro study for SLE patients and healthy subjects suggests that anti-TROVE2 autoantibodies may undergo an antibody bipolar bridging. An epitope-paratope-specific binding initially occurs to activate a hidden Fc receptor in the TROVE2 tertiary structure. This bipolar mechanism may contribute to the pathogenic accumulation of anti-TROVE2 autoantibody immune complex in autoimmune disease. Furthermore, the specific calcium-dependent protein-protein bridges point out at how the TRIM21/TROVE2 association might occur, suggesting that the TROVE2 protein could stimulate the intracellular immune signaling via the TRIM21 PRY-SPRY domain. These findings may help to better understand the origins of the specificity and affinity of TROVE2 interactions, which might play a key role in the SLE pathogenesis. This manuscript gives one of the first practical applications of two novel functions (-df/dD and Delta h/molec) for the analysis of the data provided by QCM-D and DPI. In addition, it is the first time that QCM-D has been used for mapping hidden Fc receptors as well as linear epitopes in a protein tertiary structure.We would like to thank Sylvia Daunert for her invaluable help with the discussion of the paper. Furthermore, we acknowledge financial support from the Generalitat Valenciana (GVA-PROMETEOII/2014/040) as well as the Spanish Ministry of Economy and Competitiveness and the European Regional Development Fund under award numbers CTQ2013-45875-R and CTQ2013-42914-RJuste-Dolz, AM.; Do Nascimento, NM.; Monzó, IS.; Grau-García, E.; Roman-Ivorra, JA.; López-Paz, JL.; Escorihuela Fuentes, J.... (2019). New structural insights into the role of TROVE2 complexes in the on-set and pathogenesis of systemic lupus eythematosus determined by a combiantion of QCM-D and DPI. Analytical and Bioanalytical Chemistry. 411(19):4709-4720. https://doi.org/10.1007/s00216-018-1407-xS4709472041119Kakatia S, Teronpia R, Barmanb B. Frequency, pattern and determinants of flare in systemic lupus erythematosus: a study from North East India. Egypt Rheumatol. 2015;37:S55–9.Kuhn A, Wenzel J, Weyd H. Photosensitivity, apoptosis, and cytokines in the pathogenesis of lupus erythematosus: a critical review. Clinic Rev Allerg Immunol. 2014;47:148–62.American Lupus Foundation. 2016. http://www.lupus.org .World Health Organization. Environmental health criteria 236. Geneva: WHO Press; 2006.Li W, Titov AA, Morel L. An update on lupus animal models. Curr Opin Rheumatol. 2017;29:1040–8711.Routsias JG, Tzioufas AG, Moutsopoulos HM. The clinical value of intracellular autoantigens B-cell epitopes in systemic rheumatic diseases. Clin Chim Acta. 2004;340:1–25.Franceschini F, Cavazzana I. Anti-Ro/SSA and La/SSB antibodies. Autoimmunity. 2005;38:55–63.Kelekar A, Saitta MR, Keene JD. Molecular composition of Ro small ribonucleoprotein complexes in human cells. Intracellular localization of the 60- and 52-kD proteins. J Clin Ivest. 1994;93:1637–44.Slobbe RL, Pluk W, van Venrooij WJ, Prujin GJM. Ro ribonucleoprotein assembly in vitro: identification of RNA-protein and protein-protein interactions. J Mol Biol. 1992;2:361–6.Chen X, Taylor DW, Fowler CC, Galan JE, Wang HW, Wolin SL. An RNA degradation machine sculpted by Ro autoantigen and noncoding RNA. Cell. 2013;153:166–77.Stein AJ, Fuchs G, Fu C, Wolin SL, Reinisch KM. Structural insights into RNA quality control: the Ro autoantigen binds misfolded RNAs via its central cavity. Cell. 2005;121:529–39.Reed JH, Gordon TP. Autoimmunity: Ro60-associated RNA takes its toll on disease pathogenesis. Nat Rev Rheumatol. 2016;12:136–8.Sim S, Weinberg DE, Fuchs G, Choi K, Chung J, Wolin SL. The subcellular distribution of an RNA quality control protein, the Ro autoantigen, is regulated by noncoding Y RNA binding. Mol Biol Cell. 2009;20:1555–64.Reed JH, Jackson MW, Gordon TP. A B cell apotope of Ro 60 in systemic lupus erythematosus. Arthritis Rheum. 2008;58:1125–9.Wolin SL, Reinisch KM. The Ro 60 kDa autoantigen comes into focus: interpreting epitope mapping experiments on the basis of structure. Autoimmun Rev. 2006;5:367–72.Routsias JG, Tzioufas AG. B-cell epitopes of the intracellular autoantigens Ro/SSA and La/SSB: tools to study the regulation of the autoimmune response. J Autoimmun. 2010;35:256–64.Whittaker CA, Hynes RO. Distribution and evolution of von Willebrand/integrin a domains: widely dispersed domains with roles in cell adhesion and elsewere. Mol Bio Cell. 2002;13:3369–87.Lacy DB, Wigelsworth DJ, Scobie HM, Young JA, Collier RJ. Crystal structure of the von Willebrand factor a domain of human capillary morphogenesis protein 2: an anthrax toxin receptor. Proc Natl Acad Sci U S A. 2004;101:6367–72.O’Brien CA, Wolin SL. A possible role for the 60-kD Ro autoantigen in a discard pathway for defective 5S rRNA precursors. Genes Dev. 1994;8:2891–903.Chen X, Wolin SL. The Ro 60 autoantigen : insights into cellular function and role in autoimmunity. J Mol Med (Berl). 2004;82:232–9.Escorihuela J, González-Martínez MA, López-Paz JL, Puchades R, Maquieira A, Gimenez-Romero D. Dual-polarization interferometry: a novel technique to light up the nanomolecular world. Chem Rev. 2014;115:265–94.do Nascimento NM, Juste-Dolz A, Bueno PR, Monzó I, Tejero R, Lopez-Paz JL, et al. Mapping molecular binding by means of conformational dynamics measurements. RSC Adv. 2018;8:867–76.do Nascimento NM, Juste-Dolz A, Grau-García E, Román-Ivorra J, Puchades R, Maquieira A, et al. Label-free piezoelectric biosensor for prognosis and diagnosis of systemic lupus erythematosus. Biosens. Bioelectron. 2016;90:166–73.Seo MH, Park J, Kim E, Hohng S, Kim HS. Protein conformational dynamics dictate the binding affinity for a ligand. Nat Commun. 2014;5:3724.Lakshmanan RS, Efremov V, O’Donnell JS, Killard AJ. Measurement of the viscoelastic properties of blood plasma clot formation in response to tissue factor concentration-dependent activation. Anal Bioanal Chem. 2016;408:6581–8.Fakhrullin RF, Vinter VG, Zamaleeva AI, Matveeva MV, Kourbanov RA, Temesgen BK, et al. Quartz crystal microbalance immunosensor for the detection of antibodies to double-stranded DNA. Anal Bioanl Chem. 2007;388:367–75.Shen F, Rojas OJ, Genzer J, Gurgel PV, Carbonell RG. Affinity interactions of human immunoglobulin G with short peptides: role of ligand spacer on binding, kinetics, and mass transfer. Anal Bioanl Chem. 2015;408:1829–41.Fogarty AC, Laage D. Water dynamics in protein hydration shells: the molecular origins of the dynamical perturbation. J Phys Chem B. 2014;118:7715–29.Born B, Kim SJ, Ebbinghaus S, Gruebelebc M, Havenith M. The terahertz dance of water with the proteins: the effect of protein flexibility on the dynamical hydration shell of ubiquitin. Faraday Discuss. 2009;141:161–73.Yoshimi R, Ueda A, Ozato K, Ishigatsubo Y. Clinical and pathological roles of Ro/SSA autoantibody system. Clin Dev Immunol. 2012;2012:606195.Boire G, Gendron M, Monast N, Bastin B, Ménard HA. Purification of antigenically intact Ro ribonucleoproteins; biochemical and immunological evidence that the 52-kD protein is not a Ro protein. Clin Exp Immunol. 1995;100:489–98.Gazzaruso C, Montecucco CM, Geroldi D, Garzaniti A, Finardi G. Severe hypercalcemia and systemic lupus erythematosus. Joint Bone Spine. 2000;67:485–8.Hassan AB, Lundberg IE, Isenberg D, Wahren-Herlenius M. Serial analysis of Ro/SSA and La/SSB antibody levels and correlation with clinical disease activity in patients with systemic lupus erythematosus. Scand J Rheumatol. 2002;31:133–9.Huang RY, Chen G. Higher order structure characterization of protein therapeutics by hydrogen/deuterium exchange mass spectrometry. Anal Bioanal Chem. 2014;406:6541–58.Yu F, Roy S, Arevalo E, Schaeck J, Wang J, Holte K, et al. Characterization of heparin-protein interaction by saturation transfer difference (STD) NMR. Anal Bioanal Chem. 2014;406:3079–89.Rizzuto R, Pozzan T. Microdomains of intracellular Ca2+: molecular determinants and functional consequences. Physiol Rev. 2006;86:369–408.Gaipl US, Kuhn A, Sheriff A, Munoz LE, Franz S, Voll RE, et al. Clearance of apoptotic cells in human SLE. Curr Dir Autoimmun. 2006;9:173–87.Falati S, Edmead CE, Poole AW. Glycoprotein Ib-V-IX, a receptor for Von Willebrand factor, couples physically and functionally to the Fc receptor gamma-chain, Fyn, and Lyn to activate human platelets. Blood. 1999;94:1648–56.Muñoz LE, Lauber K, Schiller M, Manfredi AA, Herrmann M. The role of defective clearance of apoptotic cells in systemic autoimmunity. Nat Rev Rheumatol. 2010;6:280–9